TNM CLASSIFICATION: The purpose of the TNM Classification is to record the extent of the disease for each cancer site. The system is based on the assessment of: the extent of the primary tumor - T, the condition of the regional lymph nodes - N, the absence or presence of distant metastases - M. REVIEW STUDY GROUPS: The proposal is to review in sequence each common form of human cancer and to prepare reports for wide dissemination. Each Study Group will (a) review existing knowledge on the etiology and pathogenesis of the human disease and available animal models of the disease; (b) identify areas most in need of investigation in patients and animal models; (c) suggest new technical approaches which might be applied with benefit to the direct study of the human disease.